1. Field of the Invention
The present invention relates to a semiconductor device. The present invention also relates to a shift register.
2. Description of the Related Art
Techniques for reducing the power consumption of semiconductor devices using logic circuits, such as processors, have been developed in recent years.
The reduction in power consumption is realized by, for example, a driving method (also referred to as power gating) for stopping the supply of power source voltages to logic circuits, memories, and the like in a central processing unit (CPU) in a period during which the supply of power is not necessary (see Patent Document 1, for example).